I enjoyed the N64 the most. Every N64 title I played I loved and they gave me hours of entertainment. Perhaps more than any system bar the Amiga. Banjo Kazooie, Banjo Tooie, Conkers Bad Fur day all amazing 3D platformers with killer stories and level design. Mario64, Zelda OOT & Majora's Mask, GoldenEye!! Paper Mario etc. etc.
There are one or two titles on the PSOne that did have me hooked (Wipeout, Medal of Honour & Underground, TombRaider) but the sheer high availability of titles and the hit-n-miss nature of the games never quite gave me the loving feelin the N64 had.
Never owned a Saturn at the time, got one free from work and never used it for a decade but came to love it for it's action RPG's. Not quite in the same league though.